Pneumatic swab



Dec. 15, 1931. H. w. FLETCHER PNEUMATIC SWAB Filed Oct. 14, 1950 Hm LbW. FLETCHER INVENTOR 1%. BY GQlQ/Uu ATTORNEY Patented Dec. 15, 1931UNITED STATES PATENT OFFICE I HAROLD W. FLETCHER, OF HOUSTON, TEXAS,ASSIGNOR T HUGHES TOOL COMPANY,

.- OF HOUSTON, TEXAS, A CORPORATION OF TEXAS PNEUMATIC SWAB Applicationfiled October 14, 1930. Serial No. 488,567.

M invention relates to pneumatic swabs emp oyed in raising'liquid fromdeep wells. The improvement lies largely in the structure of the footvalve controlling the inlet of li uid to the eduction tube.

y invention is an improvement upon the standin valve shown in" my priorapplication file August 11,1930, S erialNo. 47 4,358.

It is an object of theinvention to provide a foot valve at the lower endof the eduction tube which may be'automatically secured in positionduring operation.

I also have as an object the provision of an injector effect in causingthe liquid to flow into the eduction tube so as to obtain the desiredload of liquid above the swab plunger.

The invention resides in the provision of a foot valve easily set inposition and acting as a support for the swab plunger and a controlIneans'for the liquid from the well.

In the drawings Fig. 1 is a central longitudinal section of the upperend of the well swabbing device.

Fig. 2 is a similar section of the lower end thereof with my inventionapplied thereto.

The well has an outer casing 1, the upper end of which is equipped witha special casing head 2 with a lateral outlet 3 thereon for the liquid.Said casing head has a coupling 4 at its upper end by means of which itis connected with an elongated bull plug or housing 5 closing the upperend of the easing. Said head has an inner shoulder 6 to support the head7 of the eductlon tube. A pressure fluid inlet 8 connects through thecasing head and the head 7 of the eduction tube with the space 9 betweenthe eduction tube 10 and a larger concentric pipe 11.

The pipe 11 conducts the pressure fluid to the lower end of the eductiontube. It is connected by a coupling 12 to a housing or shoe 13. Saidshoe is closed at its lower end except for a liquid inlet opening 14.

The lower end of the eduction tube 10 fits tightly in said shoe 13 asshown at 15 and has lateral openings 16 therein to admit pressure fluidfrom the space 9 to the interior of the eduction tube. The interior ofthe shoe 13 has a downwardly tapered seat 17 to receive the foot valvemember shown generally at A.

air, the liquid in Said standin valve comprises a cylindrical housing 18tting the eduction tube. The lower end has a valve cage 19 of reducedexternal diameter, the lower extremity of which fits the seat 17 A valve20 in said cage 'is limited in its upward movement by a transverse pin21. The intermediate portion of the valve casing 18 is recessed at 22 onits outer periphery to provide space for the inlet of pressure fluid.The upper end of the standing valve member is tapered upwardly at 23 tointerfit with a wedging member 24.

Said wedging member is'tubular and fits within the eduction tube. Itslower end is flared to fit over the foot valve member and is slottedlongitudinally at 26 to allow spreading in wedging over the foot valve,thus locking the standing valve in position. The upper end of the "wedgemember forms a seat for the swab plunger 27.

The interior of the valve casing 18 has an upwardly-converging passage28 into which projects a nozzle 29 connected with the lower valvechamber. A Venturi passage 35 is formed above the nozzle.

The swab plunger 27 is of the usualconstruction. It has anupwardly'closing valve 30 which is normally held out of its seat bygravity.

In operating my device, movement of the plunger through fluid pressurewill lift the load of liquid above it to the surface and discharge itthrough elongated ports 31 and the outlet pipe 3 to storage. The plungerwill pass the ports 31 into a closed nipple 32 where it will be stoppedby fluid entrapped therein, and the valve 30 will be forced open. Theair or other ressure fluid will exhaust through the outlet andthe'plunger will begin its drop again to the bottom.

When the air pressure is relieved in the eduction tube following theexhaust of the the well will open the valve 20 andrise in the eductiontube. The pressure fluid will enter continuously through the openings 16around the nozzle 29 and will bubble through the entering oil, thushaving an injector effect creating a low pressure area about the upperend of the nozzle and drawthe upward ing liquid into the tube. The levelof liquid of the liquid in the well.

The falling plunger will be cushioned in sinking to the seat -on themember 24, and the valve will close because of the gas pressure below itand the ,air or gas will then accumulate beliw the plunger which will beraised with its load to the surface.

When the device is to be withdrawn, the wedging member 24 may be removedby a spear engaging therein, and then the foot valve may be similarlywithdrawn.

By the use of the invention, the desired level of liquid in the eductiontube above the plunger may be obtained even with a relatively low headstandin in the well, I am enabled to use my swa in wells with lowformation pressure.

What I claim as new is:

1. In a pneumatic swab, an eduction tube, a plunger therein having afluid passage therethrough, a normally open valve therein adapted to beclosed upwardly by fluid pressure, a removable foot valve housing at thelower end of said tube, and means to wedge said valve housing inposition.

2. In a pneumatic swab, an eduction tube, a plunger therein having afluid passage therethrough, a normally open valve therein adapted to beclosed upwardly by fluid pressure, a removable foot valve housing at thelower end of said tube, and means to wedge said valve housing inposition including a downwardly flaring wedge member telescoping oversaid casing.

3. In a pneumatic well swab, an eduction tube, a foot valve housing atthe lower end thereof, a valve member in said housing to control theinlet of liquid thereto, means to introduce pressure fluid to saidcasing above said valve member, a tapered upper end on said housing,means engaging therewith to removably fix said casing in said tube, anda swab above said casing engaging means.

4. In a pneumatic swab, an eduction tube, a swab plunger therein havinga fluid passage therethrough, normally open valve therein adapted to beclosed upwardly by fluid pressure, a foot valve member below said swab,an upwardly tapered end on said member, and means to engage said taperedupper end to latch said member in position, said latching means forming;a seat for said plunger.

5. In a pneumatic swab, an eduction tube, a swab plunger therein havinga fluid passage therethrough a normally open valve therein adapted to beclosed upwardly by fluid pressure, a foot valve member below said swab,and means engaging said valve member to latch it removably in positionand also serve to support said plunger.

6. In a pneumatic swab, an eduction tube, a swab plunger therein havinga fluid passage therethrough, a normally open valve therein adapted tobe closed upwardly by fluid pressure, a foot valve housing in said tube,a valve controlling the passage of liquid to said housing, an upwardlydirected nozzle above said valve, and means to conduct pressure fluid tosaid housing about said nozzle.

7. In a pneumatic swab, an eduction tube, a swab plunger therein havinga fluid passage therethrough, a normally open valve therein adapted tobe closed upwardly by fluid pressure, a foot'valve housing in said tube,a valve controlling the passage of liquid to said housing, an upwardlydirected nozzle above said valve, a Venturi passage at the end of saidnozzle, and means to conduct pressure fluid to said housing about saidnozzle.

8. In a pneumatic well swab, an eduction tube, a swab plunger thereinmovable freely from the lower to the upper end of said tube, a footvalve below said swab, means to introduce pressure fluid below saidswab, and means responsive to the flow of said pressure fluid to raisethe level of liquid in said eduction tube above the level of liquid inthe well.

9. In a pneumatic well swab, an eduction tube, a swab plunger thereinmovable freely from the lower to the upper end of said tube, means tointroduce pressure fluid below said swab, and means responsive to theflow of said pressure fluid toraise the level of liquid in said eductiontube above the level of liquid in the well.

10. In a pneumatic'well swab, an eduction tube, a swab plunger in saidtube, a foot valve at the lower end of said tube, an injector above saidvalve," and means to introduce pressure fluid through said injector andto raise the level of liquid in said tube above the level of the liquidin the well. 1

In testimony whereof, I hereunto affix my signature, this the 29th dayof September, A. D. 1930.

HAROLD W. FLETCHER.

